Initial clinical experience with the novel POLARx FIT cryoballoon system for pulmonary vein isolation in patients with atrial fibrillation

Figures

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  Fig. 1. Comparison of scar areas created by POLARx and POLARx FIT. A. Comparison of lesion size between the 28-mm and 31-mm balloon. The left figure shows a case treated with a 28-mm balloon, and the right figure shows a case treated with a 31-mm balloon. The “roof line” is defined as the line connecting the top of the upper PV and the “bottom line” as the line connecting the bottom of the lower PV. The scar area is defined as that under 0.1 mV bipolar voltage and the area is shown in gray. The total posterior scar area was calculated as the sum of half the cross-sectional area of each pulmonary vein and the scar area of the left atrial posterior wall. B. Voltage map obtained using the POLARMAP catheter after pulmonary vein isolation. In the POLARx (28 mm) group, 4 of 20 patients (40 carinae) had residual potentials in the PV carina (3 in the left carina, 1 in the right carina). However, none of 20 patients (40 carinae) in which all PVs were isolated with a 31-mm balloon size using the POLARx FIT CB exhibited residual carina potentials. PV: pulmonary vein.

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  Fig. 2. Pulmonary venographs at 31- and 28-mm balloon sizes for the LSPV and RIPV, and the number of vessels requiring balloon-size reduction to 28 mm using the POLARx FIT system. LSPV: left superior pulmonary vein, LIPV: left inferior pulmonary vein, RSPV: right superior pulmonary vein, RIPV: right inferior pulmonary vein. Occlusion grade 4: complete occlusion, occlusion grade 3: small leakage of contrast media.

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  Fig. 3. Acute re-conduction after pulmonary vein isolation with a 31-mm balloon in LSPV. (A) In this case, re-conduction of PV potential was observed after 180 s of freezing despite a TTI of 21 s and a nadir balloon temperature of − 58 °C. (B) Complete isolation was obtained by refreezing with the 28-mm balloon. Additional freezing was performed for 210 s. LSPV: left superior pulmonary vein, PV: pulmonary vein, TTI: time to isolation.

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  Supplementary figure 1. The total posterior scar area (<0.1 mV, bipolar voltage) was calculated as the sum of half the cross-sectional area of each pulmonary vein and the scar area of the left atrial posterior wall. If a scar was formed distal to the PV ostium, the scar area was defined as half of the PV cross-sectional area at the site where the scar was formed.